#2696 The effect of laxatives on reducing serum phosphate levels of probiotics in hemodialysis patients: a subanalysis of RCT

Abstract

Abstract Background and Aims Dysbiosis of the intestinal microbiota in chronic kidney disease increases uremic toxin, which damage the epithelial tight junctions and increase the permeability of the intestinal wall via endotoxemia and systemic inflammation. Some articles reported that probiotics reduced the uremic toxin and decreased inflammation biomarkers in CKD patients. Meanwhile, we have already reported that oral administration of Bifidobacterium longum in a gastro-resistant seamless capsule decreases serum phosphate levels in patients receiving hemodialysis (Clin Kidney J, 5:373-374, 2012). In addition, in this congress, we reported that three-combination probiotics decreased serum phosphate levels. Meanwhile, some articles reported the relationship hypophosphatemia and laxative abuse. The aim of this subanalysis study is to evaluate the efficacy of laxatives on reducing serum phosphate levels of three-combination probiotic in patients receiving hemodialysis. Method A 6-month prospective, randomized, double-blind, placebo-controlled study was conducted at three hemodialysis centers. As probiotic therapy, of three-combination probiotics (Bio-Three) tablets, each containing 2 mg of lactomin (Streptococcus faecalis T-110), 10 mg of Clostridium butyricum TO-A, and 10 mg of Bacillus mesentericus TO-A, were used. The patients receiving hemodialysis were randomly assigned to the Bio-Three group (n = 37) and the placebo group (n = 36). In both the Bio-Three group and the placebo group, patients orally received 6 tablets 3 times daily. We evaluated the effect of probiotic on serum phosphate level and gut microbiome before and 6 months after the start of treatment. The gut microbiome composition was analyzed by a 16s rRNA gene-based sequencing protocol. In addition, in patients with laxative (n = 24), we evaluate the effect of probiotic on serum phosphate levels and gut microbiome. Results The serum phosphate levels in the Bio-Three group significantly decreased after 6-month treatment, while did not change in the placebo group. Furthermore, the serum phosphate level in patients with Bio-Three and laxative additionally decreased. In a 16s rRNA gene-based sequencing protocol analysis, serum phosphate levels were positively correlated with the occupancy ratio of Erysipelotrichaceae, Lachnospiraceae, Oscillospiraceae, Ruminococcaceae, and Sutterellaceae and were negatively correlated with the occupancy ratio of Leuconostocaceae and Lachnospiraceae in patients with Bio-Three and laxatives. Conclusion In this subanalysis study, the effect of reducing serum phosphate levels on three-combination probiotic might be augmented by laxatives and the specific bacteria in the gut microbiome might contribute to the decrease of serum phosphate levels.